This invention relates to an apparatus for prompting the performance of cardio pulmonary resuscitation (CPR).
In this specification, CPR comprises the performance of expired air resuscitation (EAR) concurrently with external cardiac compression (ECC) in accordance with the specifications laid down by the Australian Resuscitation Council.
EAR is used on persons suffering from respiratory arrest, the essential signs of which are unconsciousness and absent respiration. On the other hand, ECC is used on persons suffering from cardiac arrest, the essential signs of which are unconsciousness, absent pulse and absent respiration.
The performance of EAR involves the following steps:
the rescuer pinching the casualty's nostrils between finger and thumb of the hand, and extending the head of the casualty to maintain the airway open; PA1 the rescuer opening his/her mouth wide and taking a deep breath; PA1 the rescuer placing his/her mouth firmly over the casualty's mouth making an air tight seal; PA1 breathing firmly into the casualty's mouth, watching to see that the chest rises; PA1 the rescuer removing his/her mouth, watching to see the chest of the casualty fall and listening for the breath exhaling; PA1 continuing rhythmically the breathing and watching procedure in accordance with a prescribed rate dependent upon the age of the casualty. PA1 placing the casualty on his back on a firm surface; PA1 kneeling beside the casualty's chest at right angles to the line of his body; PA1 locating the lower half of the sternum of the casualty; PA1 the rescuer placing the heel of one hand at this point, keeping the palm and fingers raised from the chest; PA1 covering this hand with the heel of the other hand; PA1 the rescuer keeping his/her arm straight, rocking forward over the casualty until the rescuer's shoulders are vertically above their hands; PA1 pressing briskly down to depress the sternum about five centimeters; PA1 rocking backwards releasing the pressure from the sternum; PA1 continuing rhythmically with the aforementioned depression and release of the sternum at a prescribed rate dependent upon the age of the casualty. PA1 input means for sensing an input signal input by the operator, in response to an input prompting signal output by said apparatus; PA1 display means for displaying a plurality of visual prompting signals to said operator; PA1 audible means for outputting an audible prompting signal to said operator; and PA1 control means for controlling the sequencing and operation of said input means, display means and audible means to generate said prompting signals in accordance with a prescribed protocol based on prescribed CPR techniques; wherein: PA1 (i) said input prompting signals are controlled by said control means to prompt the operator to ascertain the presence of a pulse of the casualty, specify the number of rescuers performing the resuscitation, and specify the age status of the casualty; PA1 (ii) said visual prompting signals are controlled by said control means to provide said input prompting signals and also to prompt the operator to perform either or both heart compression and lung inflation on the casualty at a prescribed rate in accordance with said CPR technique; and PA1 (iii) said audible prompting signal is controlled by said control means to supplement said visual prompting signals.
The performance of ECC involves the following steps:
In the case of cardiac arrest, it is necessary to use a combination of EAR and ECC, i.e. CPR. The performance of CPR varies depending upon whether one rescuer or two rescuers are available, whereby in the case of two rescuers one may perform EAR and the other ECC contemporaneously. In the case of there being only one rescuer, it is necessary for the one person to perform both EAR and ECC.
In practice, upon encountering a person who has suffered respiratory or cardiac arrest, the first symptom which can be readily ascertained is whether the person is unconscious or not. In accordance with the specifications set down by the Australian Resuscitation Council, at this stage the air way of the unconscious person should be cleared and opened to ensure that the person can breath.
The next obvious symptom which can be ascertained at this stage is whether the casualty is breathing or not. Accordingly, after the air way is cleared and opened, the casualty must be checked to determine whether they are breathing or not. In the event that they are not breathing, the rescuer must immediately enter into EAR technique, providing five inflations as rapidly as possible since time is vital at this stage.
After this, the characterising symptom for cardiac arrest can be checked, i.e. whether the pulse of the casualty is present or not, to ascertain whether the casualty is suffering from respiratory or cardiac arrest.
If the pulse is present, it can be ascertained that the casualty is suffering from respiratory arrest only and accordingly EAR procedure may be continued at the rate of twelve inflations per minute for an adult casualty and at the rate of twenty inflations per minute for a child or baby casualty.
This procedure is continued for one minute at which time the pulse is again checked, as the heart may have stopped beating. If the pulse is still present, EAR is continued at the prescribed rate for further periods of two minutes each, with the pulse being checked for five seconds at the termination of each two minute period, until the casualty recommences breathing.
If at any time during a pulse check it is determined that the pulse is not present, then the rescuer must immediately enter into ECC procedure and perform this in conjunction with EAR procedure. In view of the two discrete procedures involved, it is better for the performance of CPR at this stage to be performed by two rescuers, one performing EAR and the other ECC on the one casualty.
When two rescuers are available, CPR procedure should proceed at the rate of five compressions (ECC) to one inflation (EAR) for an initial period of one minute in the case of an adult, one operator performing ECC in five second cycles at the rate of one compression per second, and the other operator performing EAR timing his/her action to make one inflation of the chest between the fifth compression of one cycle and the first compression of the next.
After the first minute the pulse is checked and if the pulse is returned, ECC is dispensed with and EAR is continued as previously described in two minute periods, with the pulse being further checked after each period. If the pulse is not present, the combined ECC and EAR procedure is continued for two minute periods with the pulse being checked again after each period.
In the case of children, the compression and inflation rate is changed to suit so that 5 compressions are performed at the rate of 100 per minute followed by one inflation.
If only one rescuer is available, then CPR procedure must be altered to accommodate the one person performing both ECC and EAR. In this regard, upon the rescuer determining that the pulse is absent, ECC is performed continuously for 15 chest compressions at a rate of about 80 compressions per minute, whereinafter EAR is performed for two inflations of the lungs over a period of approximately 5 seconds. Thereafter, the cycle of 15 chest compressions and 2 lung inflations is continued at this rate again for an initial period of approximately 1 minute, whereinafter the pulse is checked. If the pulse is still not present, CPR is continued to be performed for periods of two minutes with the pulse being checked at the conclusion of each two minute period for a period of no more than five seconds.
It should be noted that the pulse checking procedure is very important and determines the subsequent procedure to be performed by the rescuer.
As can be appreciated from the above description of CPR procedure, although the procedure is logical, unless it is practised regularly, it is easily forgotten. Indeed, if it is remembered, it can be difficult to perform correctly and accurately, particularly in regard to the timing rates of chest compressions and lung inflation. In practical terms, the need for practising CPR arises only in emergency situations and in the majority of cases a person may never encounter an emergency requiring the performance of CPR technique, or may only encounter the same in an unexpected occasion once or twice in a life time.